A wide range of forms of voltage converters, such as inverters for producing one or more AC or phase voltages, are known. Examples of inverter topologies are ANPC (active neutral point clamped), NPC (neutral point clamped) or MPC, cascaded H-bridges and the like, which each have specific characteristics. In many topologies of inverters, a switching unit exists in which high voltages are switched in the range of the voltage shift to be provided in the output voltage, at a high frequency, in order to produce the desired voltage waveforms at the outputs of the inverter. This requires corresponding design of the power components used, as a result of which the conventional topologies of inverters are complex to implement.
Furthermore, some of the conventional inverters have intermediate circuit capacitors in order to produce intermediate point voltages, by means of which a plurality of voltage levels can be produced for operation of the inverter. These capacitors are in general susceptible to ageing, thus limiting the life of such inverters.
U.S. Pat. No. 6,104,624 discloses a conventional converter apparatus which has two selection elements. Only a single intermediate voltage potential is applied to each of these two selection elements, and each selection element can then select only this one intermediate voltage potential for outputting as the respective output voltage potential.